[mattmanser]

    fruit = fruit === "" ? "" : fruit || "strawberry";

Woohoo! Javascript rocks! Note that

    fruit = fruit == "" ? "" : fruit || "strawberry";

May or may not be bugged depending on your understanding of a bug and whether you're a marmite fan.

[tracker1]

    fruit = fruit === "" && "" || fruit || "strawberrry";

It's flexible too.. though imo your ternary operation is more obvious. ;-)

Personally, I find that once you understand JavaScript, the beauty in what you can do, especially for input validation (which is an ugly, ugly thing) works so well in this language.

[zaf]

And what about the check for 0? Or does the empty string handle that case as well?